“Sam, wake up!” Were the first words Sam heard in the morning, his mother waking him up earlier than usual for the family cruise. “Alright, alright… I’m awake.” Sam said in a low, morning voice. “It’s already 8:45 AM!” His father shouted from across the hall. “Come on, you heard your dad.” Mom said in a much lower voice. Mom exited the room, and went to wake up Katie, Sam’s older sister by 1 year. Sam and Katie were really close at childhood; puberty separated them a bit but they still talked all the time. And Katie was a very attractive 19-year-old, she acquired the same incredible genes her mother had. She had a mixture between a spoon and an hourglass figure, and a pair of boobs which attracted every man in the college campus. She also had long brown hair which was as loose as the dresses she wore. Other than college, she liked to wear loose dresses, whether it was a sundress or a nightgown, as long as it felt comfortable and reviled a little bit of her. Sam got out of bed quickly, still in his underwear, he took a towel, and went to the bathroom to shower. Katie got out of bed quickly, still in her nightgown, she took a towel, and went to the bathroom to shower. “I’ll go first! I need this shower more than you do.” Katie broke the silence is they were both standing in front of the bathroom door. “Hey, you’re not the only one who’s hygienic. I need this shower too!” Sam shot back. “It’s 8:55 AM, we need to be there at 9:30. There’s no time for both of you” Their father said as he was passing by. “Sam, look, I’ll shower now and you can shower on the crui—” “There is no shower on the cruise.” Father interrupted as he was climbing down the stairs. “You heard him.” Sam replied. “There’s no reason why you should shower and I shouldn’t.” “Well… The opposite is also true.” She replied trying to justify herself. “There’s also no time for arguing, you either shower together or no one is showering.” Father said still shouting “I don’t have a problem with it, your mother doesn’t ha— hey honey do you have a problem?” “Not at all.” Mother replied so as to agree with their father. “So now, you’ll have to sort this out by yourself, because if it hits 9:05 and you’re still arguing, I’m leaving you behind” He said in a much lower voice. Sam and Katie paused for a second… and thought about what to do. “So…” Sam asked. “So?” Katie replied. “let’s say yes or no at 3, 2, 1…” Sam proposed. “Yes” They both said in one voice as they chuckled. “Ok, let’s not… make this awkward, it’ll be like when we were kids, remember?” Katie said. “Sure… yeah… no awkwardness” He replied in awkwardness. They both went into the bathroom and closed the door after them. Katie, wearing her nightgown, decided to take it of first. The gown was incredibly revealing by itself, and she was about to reveal even more. Sam’s heart started beating very fast, what if he gets turned on, what if his dick gets hard, the shower is already small, and his 6-inch dick wasn’t going to make the situation any better. Katie took off her nightgown, exposing her incredible body. She had two amazing 38C breasts, with small pink areolas that were not perky, but definitely hard. And a tight, shaven pussy above a small but barely noticeable gap. “Your turn” She said. Sam did the same thing, he took of his underwear, revealing his semi erect dick. His heart fell to the ground after he saw his dick just a few centimeters away from his sister’s pussy. Katie shuffled backwards, trying to get a few inches away from Sam’s cock. He stepped back saying “Maybe I should leave; you can have the shower.” “No, don’t” she said as she pulled him from his elbows closer to her. She pulled him too close though since they were now embracing. “uhh… s- sorry… I really didn’t mean to—” “Hey it’s fine, don’t worry about it.” He replied. “Ok, but please don’t leave, I’m fine too” she replied quickly They both enter the shower, which was very tiny—not more than 10 feet squared—and it got cramped very quickly. It was almost impossible for Sam not to grind his cock all over her body, her pussy, ass, and her thighs. He kept apologizing every single time at first but that got stupid very quickly. His dick was also not slowing down anytime soon, it was fully erect at that time with a small bit of pre-cum coming out of the tip, luckily the water took it down drain with it. A few seconds of shuffling later, Katie started applying her shampoo, she had long hair so she put a lot of it, almost too much. The shampoo started flowing from her shoulder and down her back, all the way to her ass crack and more, it was not practically every where on her back and ass. That didn’t help Sam as it made it easier for his dick to grind on her with the lubrication. Sam bend over her to get the soap, “excuse me” he said as he pressed his dick on Katie’s ass, which made her moan softly. The feeling of his huge cock on her tight ass and pussy, the lubrication from the shampoo made it flow easier. She couldn’t handle it anymore; she was too aroused. She started moving up and down while moaning softly, that made Sam’s dick go between her ass cheeks even further, she kept doing this more and more, her moans louder and louder. By that time Sam had already gotten his soap, but he kept his dick on her ass, he too was very aroused. “Ahhh!” she said in a soft voice. She started pushing even more, bobbing up and down, moaning harder. And Sam did the same thing, he started pulling and pushing, his dick was now touched her anus wanting to get inside it. “Ohh… Ahh... come one just go inside me” She said in a low, needy voice. “This is so wrong, I can’t” He replied as he pulled back away from her. “No, you can’t” She replied desperately “I need you, give it to me!” “I can’t fuck my sister, Katie” “No, please, I’ll do anything. Just please fill me up” She said. “No- Just…” He stuttered. “Ok, only if you can make me cum in 2 minutes” “I’ll do anything for you, anything for daddy” She replied happily. “You’re weird” He stated. Katie pinned Sam to the wall and took his dick and shoved it inside her, she started moaning as loud as she can. She didn’t care—at the moment—if their father or mother heard her, or even George who was their 7-year-old brother. “Dude, you’re gonna get us killed, shut up!” Sam said as he covered her mouth with his hands. At that moment, Sam had his back to the wall, he had one hand on his sister’s waist and one hand on her mouth whilst fucking her, and she was bent over and holding his ass cheeks with both hands, “Oh god, I’m gonna cum” Sam said “You’re really good at this”. In fact, Katie was a PROFESSIONAL at this! She gave Sam the best orgasm of his life one and a half minutes after they started, he couldn’t stay any longer. Ropes of cum burst inside Katie’s pussy, filling her up to the brim in the process. Sam pulled out soon after that. As he took his dick out, cum started dripping from Katie’s vagina, there was no space for all the semen he placed inside her. “You’re… dripping” Sam said. “Yeah, it’ll stop soon.” She replied as she was drying herself with a towel. Katie finished drying, then Sam, but she was still dripping with cum. “It hasn’t stopped” Sam told her “When was the last time you masturbated?” She asked “You had all of that inside you and you didn’t wanna fuck me?” “You’re my sist—” “Sam, honey, can you just forget that I’m your sister? Please, for me.” She said “For the rest of the day, afterwards we won’t fuck again” “whatever you say, mommy” He replied mocking her. “Shut up” She said grinning. “So what? Are we going to do this more?” Sam asked. “For the rest of the trip… if you want” she replied slowly. “As I said, I’m happy if you are” He replied. more to come if you want.